The Satoh Bull S-630 tractor was built in Japan by Satoh. Models in the 1970s (s630g) may have had the Mazda engine. Mitsibishi acquired Satoh in late 1970s and began using 22 hp mitsubishi engines. These models are the s630 (2wd) and s630d (4wd) It features a 15 hp (11 kW) Mazda engine.[1]